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Topic: Sparkfun Serial Motor Driver (Read 8289 times) previous topic - next topic



For the life of me I can't get this thing to work. I reloaded the firmware since it would just turn on and both stat LED's would be lit. No matter what I do it won't turn the motors on.

I have it at 115200 and nothing. I get a ready on startup too. Whenever I send a command I get the command echoed back on the serial.

Even if I make the command too long, whatever I sent gets echoed back.

I am running a Arduino Mega and the motors have been tested.

Anyone have experience with this controller?


I got the same experience with it as you do... And finally when I got it working, it kept shutting off because of the short initial current the motors draw.

Instead I changed to this http://www.seeedstudio.com/depot/l298-dual-hbridge-motor-driver-p-284.html
captain-slow.dk | non contagious!


Jan 27, 2011, 08:28 pm Last Edit: Jan 27, 2011, 08:31 pm by MobileWill Reason: 1
Thanks, how did you get it to work? I changed the limit in the firmware to 3.5 so I think if I get it to work it will stay working.

Thanks for the link, i think i saw that somewhere in my searches. That would be a last resort. How do you control that one?

I think I will read the firmware some more and see if I can't figure it out. Sparkfun support hasn't responded yet.

I wish it had a connection for separate motor power too. I would rather run the motors at 3.7 from my battery.

BTW how is their shipping times? I am in CA.


Thanks, how did you get it to work?
I didn't ;) I messed around with it for some hours, then threw it away.

I don't know how long it takes to your place, but from seeedstudio and to me (DK), it takes between 2 and 3 weeks, but a lot of that is also customs.

To control the motor driver I posted a link to, you use 4 digital pins to set the direction each motor will go, and then a PWM for each of them to set the speed they should run at.
captain-slow.dk | non contagious!


Wow that uses a lot of PINS? Hmm I have a mega, I might have enough PWM pins, only using 2 for servos.

I think I can get it faster from robotshop as I am in the states.

Plus I need a good regulator... hmm. Thanks. I hate to throw it out, maybe re purpose it.

I will fiddle with it some more tonight. Did yours echo back what cmd you sent it?


Did yours echo back what cmd you sent it?

Yes it did, along with whimpering about too much current being drawn.

The dual H-Bridge is using 6 pins yes, which might be many on an UNO, but for a mega (which I am using on my project too), it isn't an issue, unless you really fill it with sensors ;)

What I also like about the driver, is that it responds a lot faster than the serial one, because you don't first compile a message to send to it, then the controller processes that message, then does what it was told (maybe), the simple driver is just doing what you set the controller's pins to. Can't be much faster than that. :)
captain-slow.dk | non contagious!


hmm... Then I wonder why it isn't executing the command?

I fixed the current by setting it to 350 in the firmware.

That is a good point. So could I use pins 22+ for 2 servos and the motor drivers?

I do have a bunch of sensors but have plenty of pins. Most of the sensors are simple and one uses i2c. I haven't gotten to touching them yet.

I get a buzzing from the motors but no movement.


The buzzing was all I ever got too, and only for like an half second.

I am using these pins for my motor driver
Code: [Select]
//H-Bridge pins
#define I1 41
#define I2 40
#define I3 39
#define I4 38
#define EB 4 //PWM
#define EA 3 //PWM

I1, 2, 3, 4 is the same as the silkscreen on the driver's board.
captain-slow.dk | non contagious!


Hmm I will have to try and get a refund or something.... I knew there were firmware issue, but not, not working at all.

The buzzing stays for me, probably because I changed the limit.

I could do PWM on other pins right? Seems like the mega can route PWM to other pins at least for servo. Does that work for this?

I might be able to use like 9/10 but I have to see how the voice shield reacts since the events pins are connected even though i am not using them.

I have a adafruit motor shield on another robot tank, but uses a lot of pins and its a shield, so this will work.

Thanks. See how tonight goes.


I haven't tried pwm on other pins than the ones I am using, and the wires are soldered on now with heat shrink tubing, so I am not going to test if I can get it to work on other pins too. :)
captain-slow.dk | non contagious!


LOL, I was just seeing if you knew. I have the servos working on 22/23.  I guess I better order soon, what to get this robot moving by mid Feb.



Do you think it will work with a 3.7-4.2 power for the motor and then 5v for the logic?

It works with adafruit shield.

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